Bees, despite their sesame seed-sized brains, are smarter than we think.
“Often people view insects as unthinking machines,” says Clint Perry, a biologist who studies the evolution of cognition in insects at Queen Mary University of London. Science has recently challenged that human-centric assumption, by revealing that the busy buzzers can use tools, count to four, learn “foreign languages" and even experience some semblance of sugar-derived happiness—traits usually associated with larger-brained animals.
Now, Perry and his colleagues have released the results of a creative new experiment in which they essentially taught bumblebees how to play "bee soccer." The insects’ ability to grasp this novel task is a big score for insect intelligence, demonstrating that they’re even more complex thinkers than we thought. Moreover, they did it all not just in spite of their tiny brains—but because of them.
For the study, published in the February 23 issue of Science, researchers gave a group of bees a novel goal (literally): to move a ball about half their size into a designated target area. The idea was to present them with a task that they would never have encountered in nature. Not only did the bees succeed at this challenge—earning them a sugary treat—but they astonished researchers by figuring out how to meet their new goal in several different ways.
Some bees succeeded at getting their ball into the goal with no demonstration at all, or by first watching the ball move on its own. But the ones that watched other bees successfully complete the game learned to play more quickly and easily. Most impressively, the insects didn't simply copy each other—they watched their companions do it, then figured out on their own how to accomplish the task even more efficiently using their own techniques.
The results show that bees can master complex, social behaviors without any prior experience—which could be a boon in a world where they face vast ecological changes and pressures.
Knowing some of the things bees are capable of might also inspire humans to do a bit more to aid their survival, adds Perry. “We often put ourselves atop a hierarchy, where we're smart and we have large brains, and anything far removed from us physically or morphologically, especially animals with small brains, must be not smart,” he says. “Understanding that bees and different insects have more complex cognitive abilities can allow us to appreciate them more. And it might help our efforts to manage living with them a little better.”
Previous research has shown that bees can learn from one another when performing tasks that resembled the forging and other behaviors they perform in the wild. For example, Perry and colleagues reported last year that bees could teach each other to pull strings attached to faux flowers for a tasty reward. But Perry wanted to test whether bees could truly learn a behavior unlike anything their evolutionary ancestors were likely to have performed.
“Even more complex tasks like communication or navigation are genetically preprogrammed and not really flexible,” he says. “What we really wanted to do is to test something unnatural, as far removed as we could outside what they would normally do.”
Scientists gained some insight on just how the bees learned by changing up the conditions of the game. For some bees, researchers provided no demonstration at all of the game’s objective, but merely a reward if the insect somehow succeeded. Two individuals still figured out the task, but most struggled. Other bees were shown a “ghost demonstration,” in which the ball moved to the goal controlled by a magnet. Around 80 percent of the bees learned to complete the task this way.
The most effective method was having bees learn by watching a previously trained bee perform the task. Every single bee that was taught this way learned the game correctly, and learned more quickly than the others. But the bees not only copied their companions—they also improved on what they'd seen and added their own flair to complete the task more efficiently.
There was one cognitive leap that especially impressed Perry and colleagues. In the bee demonstrations, demonstrator bees were trained with a setup in which only the farthest away of three balls was mobile, meaning they always moved that most distant ball. Untrained bees then watched a demonstrator perform the task in this same way, three times. Yet when they were given a chance to perform it on their own, they moved the closest ball—even though they'd never seen it moved before.
“Yesterday [co-author Olli J. Loukola] and I were wondering whether we would actually pick a closer ball,” Perry says. “If we were in a similar test with basketballs at a gymnasium would we try the closer ball or just go to the one that we saw someone use successfully? I think that I would probably just copy what I saw because I wouldn't want to risk not getting the reward.”
The new study helps demonstrate that how an animal thinks depends on its lifestyle, says Felicity Muth, a bumblebee researcher at the University of Nevada, Reno. Although the ball-rolling behavior isn't part of a bee's life, the cognitive powers that make it possible are a product of that environment, she says.
“We have this assumption that animals that look more like us are capable of complex cognition,” says Muth, who studies the cognitive basis behind bee foraging. “And it doesn't work like that at all. Bees have to learn things constantly … a bee can visit thousands of flowers in a single day and they can learn what colors of flowers have certain rewards. Bees learn shapes, patterns, textures. They can even detect the electromagnetic field of a flower and make associations with different fields.”
NASA has even sent bees into space, and found that they rapidly adapt their flight patterns to a near-zero gravity environment.
David Roubik, a bee expert at the Smithsonian Tropical Research Institute in Panama, adds that bees can not only see and imitate another moving object, but they also gather olfactory, tactile and even auditory information as well.
“Learning takes place, for the social bees at least, on the broad stage of foraging and interacting with the outside environment, and doing a variety of other things, in more or less total darkness, within the nest interior,” he notes. “Because the same bee will have both venues to pursue, if it lives long enough, an acute adaptive flexibility is required. This is evidently what has taken place, in a novel new setting, in the bumblebee study reported here.”
Bees are well-known for the social dynamics and swarm intelligence that exists within the hive, a system that Thomas D. Seeley dubbed “honeybee democracy.” In 2010 book by that title, he investigates the bees' heated debates and collective decision making on life and death issues, such as how to choose sites for new colonies and navigate to them en masse. Honeybees are also famed for their booty-shaking method of communication, in which workers use symbolic gestures to describe and recruit others to a particularly tasty food source or promising new nest site.
The insects will need all of these intellectual strengths to deal with the multifaceted threats that have decimated many populations. A two-year study released by the Food and Agriculture Organization of the United Nations last year reports that growing numbers of bee and other pollinator species worldwide are threatened by extinction. That’s bad news not just for pollinators, but for us: The same report estimates that 75 percent of the world's food crops depend on pollination, at least in part, and the annual value of the crops directly impacted by pollinators may top $500 billion.
Could bees’ surprising cognitive abilities help them to overcome such vast challenges? Perry says that their flexible minds may well help them adapt in smaller ways, like accessing food in new environments. But when it comes to the larger changes that are reshaping their ecosystems—climate change, pesticides and agricultural or urban development—it’s up to us to do the adapting. “I think most of the bigger problems they face are ones we'll have to deal with,” he says.